nathanUK '81 930 G50

Do yourself a favour and get an Innovate setup.

Mark Houghton

Correct me if I'm wrong Nathan, but is the Innovative on-board AFR setup what a person should be using while sitting at idle, trying to dial in the initial AFR? No doubt that it's the thing to have for monitoring everything across the entire engine performance range. If I read you right, you would recommend spending hard-earned money on the Innovative (LM2), vs. on a Gunson Gastester which has good - though limited - use. Of course, I took the hard way around and started with the Gunson, then added an AFR gauge (pre-LM1), so now I need to go after an LM2. But I think I'll keep the old Gunson anyway.

WPOZZZ

Do you remember what I told you?

Akila

Bryan,
Yes I remember, but this was just a small thing, easily fixed. Was just suprised & I though of what you told me. All's well..

F350Lawman

Hey, don't get discouraged. Just this weekend my car sounded like I either broke a header or... GULP...broke a head stud. It sounded like a VW bug on throttle. My mechanic looked nervous until we got it on the lift and he saw the little plug in the block where some emmisions "nonsense" had been plumbed (when we had any such nonsense on the car ) had fallen out. 30 seconds and 1 little plug later, I was back in business.

Total cost = ZERO..just a tad better than a top end rebuild.....no???

WPOZZZ

Glad you got it squared away.

nathanUK '81 930 G50

I understand what you are saying BUT considering how much these engines would cost to rebuild, a high quality accurate AFR setup seems very cheap indeed. One may as well put the cost of a Gunson towards an AFR setup.

Oh, I've tuned a SU carb with a Gunson and a file in my younger days after fitting a K&N air filter assy to it. This caused the car to lean right out.
I looked at the gauge in my rear view mirror and filed away at the needle until I got the curve right

Mark Houghton

I'm with you on that...cheap insurance. The Gunson works in a pinch, but increased accuracy with an AFR setup can only be a good thing.
I can remember the days of dialing in SU carbs myself...without a Gunson. For that matter, I still own a 1960 MGA...with the SU's stored away and a Weber on the car instead. The Gunson has helped to dial it in. At least with the MG (basically a tractor motor) if the mixture is off it will just run like crap and not melt down like a 930

nathanUK '81 930 G50

Yeah, I didn't even consider any damage to running this normal, water cooled NA car lean. My mates thought I was mad driving the car with a sniffer up the tail pipe with the unit on the back shelf LOL.

I can tell you that it worked a treat and the car ran great.

Shaka

Hey Akila,

You checked for intake leaks and was not able to find any but have you checked the seals at the BOV or also called the Boost Valve Housing?
Part # 930-110-149-00

Your symptoms sound familiar and IIRC I stumbled across these deterioriating seals and replacing them took care of my erratic idle and the bogging at the onset of boost.

Just a thought...

I do think a good AFR gauge like innovate would be helpful to diagnose your problems. I got one awhile back and by monitoring AFRs at idle and at speed helps me isolate issues.

David

Akila

I have in fact changed out those seals on the BOV. I had done this in one of the seems like many times I had the intercooler off. NO MORE CLICK!! Sounds so much better. I have used carb cleaner & propane to try to locate leaks, to no avail. I finally got to adjusting AFR & seems to have worked wonders so far, just dont know exactly where my CO2 mixture readings are with no meter, hence the discussion.
I talked to my Brother yesterday, who is having smog woes in Ca. suggested he buy a Gunson, & when he is done send it over to me. He seemed to agree. For now I just have the light stumble coming on at 3300-4000 rpm that has got me scratching my head again. You think it might be low Octane fuel? I had to use about 5 gallons of regular when I thought it might be my fuel pressure or sending unit.

911addict

The Gunson says it is accurate to +/- 0.5%!!! Big difference!

Mark Houghton

True, but when your CO is off by perhaps several percent, at least it gets you back into the ballpark. That was the case when I first began tuning my 930 after purchasing it years ago. Again, the Gunson is only really any good for preliminary setup in the driveway. Thus, a nice AFR setup per Nathan's earlier comments is the best of both worlds.